Figure 2.

Superimposed images of flagellar movement of activated and hyperactivated bull spermatozoa. The spermatozoa attach to a glass slide by their heads; thus, detailed information on the flagellar movement of individual spermatozoa is readily obtained. A: Activated spermatozoa. B: Hyperactivated spermatozoa with asymmetrical flagellar movement. C: Hyperactivated spermatozoa with fairly symmetrical flagellar movement. The bull spermatozoa generally beat with three-dimensional flagellar movement, but the asymmetrical flagellar movement of the hyperactivated spermatozoa is particularly out of focus (Table 1). Bar, 20 µm.